"Hot Tub Time Machine" has highs and lows as it spins along.

The screenplay by Josh Heald, Sean Anders and John Morris wobbles between the predictable gross jokes involving every fluid in the human body and some surprisingly smart commentary about friendship and the absurdity that was the 1980s.

Adam (John Cusack), Nick (Craig Robinson) and Lou (Rob Corddry) are three 40-something buddies who decide to escape their failed lives by returning to a ski lodge that provided many happy memories from their youth.

Adam drags his nerdish nephew Jacob (Clark Duke) along, just to get him away from the computer screen.

The lodge is in disrepair, except for a hot tub in their room. What starts as a drunken soak ends up sending the four back in time to 1986 -- aka a time of leg warmers, Alf, Ronald Reagan and sexual freedoms.

A mysterious repairman (Chevy Chase) warns the guys they can't change anything or it might affect the future.

Most of the smarter jokes come from Jacob, who is an outside observer to this whole weird world. Sadly, for every smart joke about '80s hair, colorful wardrobes and technology, there is one that sounds like it was pulled from the raunchy comedy "Porky's."

The unevenness goes beyond the writing. The casting of Crispin Glover to play a one-armed bellman is brilliant because he starred in one of the biggest time-travel movies of all time, "Back to the Future."

But the writers failed to take advantage of Cusack's casting. It would have been funny to see references to his mid-80s movies like "The Sure Thing," "One Crazy Summer" or "Better Off Dead."

Overall, there are more good jokes than bad ones in "Hot Tub Time Machine." That means there's no need to heed Nancy Reagan's famous '80s advice "to just say no."